Harvey huber eslinger



July 8, 1930,.

H. H. ESLINGER SAFETY DEVICE FOR INTERNAL COMBUSTIQN'ENGINES Filed April 5, 1928 INVENTOR.

ATTORNEY Patented July 8, 1930 r HARVEY HUBER nsnmenn; orv ILA-roarsnn iaer, rnnnsynvnnm; ssrenon or 561m;

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rounrn 'ro cent Henson, or H RRISB RG, rEnnsYLvAnIA SAFETY DEvrcn non INTERNAL-COMBUSTION ENGINES Application filed April 3,

mal conditi'on'in the functioning of the en'- gine for grounding a circuit upon which the normal operation of'the' engine depends, for instance, the ignition circuit, thereby automatically stopping the engine until the'said untoward condition can be rectified.

One of the objects of the invention is the provision of a 'deviceof" the class described which can readily be applied as an attachnow existing; Another object of the invention is to provide a shunt circuit connected into the primary circuit system of the ignition system, whereby arcing at the interrupting element 0r elements is avoided and long lifeand reliability in the operation of the system -as-' sured. e 'Still another object of the invention is to provide positively operated auxiliarymeans for rendering'the shuntfcircuit inactive, at

times when it is desired to operate the engine notwithstanding the absence of certain con ditionscharacteristic of the normal running state of the engine. For example, when'the device is so designed'that'closingof the shunt" circuit with consequent interruption of the ignition system, is responsive to low pressure in the lubrication system, it would be impos-' sible to start the engine, since the oil pressure remains nil until the engine is started and the shuntcircuit would consequently remain closed.

A further object of the invention is the pro vision of an auxiliary safety shunt circuit, with actuating devices, controlled as de scribed by abnormal engine conditions, either of pressure ortemperature or both, said circuit being connected into the primary ignition circuit at a point between the transformer and breaker points, at a part of the circuit operating with relatively low amperage;

' Other objects of theinvention will appear as the following description-of a preferred embodiment thereof proceeds. l i r In the drawings in which similar characanism of, the engine. v

r the primary winding 1923., Serial no. 261092. v ters ofreference are used throughoutto iden-J tifythesameparufl Figure 1 1s aidiagrammatic view,partlyin longitudinal section of the electrical ignie tion system of an internal combustion en gine, showing the automatic interrupting circuit of the present invention together with mechanical embodiments of theseveral inter-- rupting organs. through which the (system isoperate.

.Figure 2 is a viewtin perspective showing v a modified feature of the invention in which the relief switch is combined withthe-choke' rod associated-with the fuel supplying mech- Referring nowin detail to the several figures the numeral 1-, represents partbof the 7 engine cylinder block in longitudinal sec;- j tions, the spark plug being represented, at2 Y and being in .thejsecondary circuit 8ofa transformer coil 4, the. primary circuit-,5 or" which includes a source of current 6 ground-;

ed asusual through the breaker points fi.

' The spark plug is ofcourse, gr ounded in the usual manner, to the 'engineblock and of the coil is grounded as'shown at7. l l 7 An ignition switch 8 is. intercalated (in the 1 primary cir;cuitbeingpreferably convenient-i) ly located upon the instrument board-9 ."i,-

vso

All that has been described up to thispoint is of conventional construction andarrangement and the present lnvent1onbeglns wrth single wire 9 which taps the primary ignition circult at any des redrpo nt, for nstance,

at the binding screw 10 of the primary; wind .theauxiliary shunt circuit, consisting of the 1,

ground in this shunt circuit consists of afi normally opensWitch or interrupter con trolled either thermostatically or, by fluid pressure so as to close upon a predetermined rise of the engine temperature or an abnor- 'Inal pressure change in some p essure factor incident to the engineoperatlon, such as predetermined subnormal pressure} value 1 the'lubricat-lon system.

In the present instance there are" two' 'interrupters in the shunt circuit, arranged in electrical parallelism and independently automatically operable to close the shunt circuit.

One of the interrupters comprises a thermostatic element 11 arranged to be within the influence of the heat of the cylinder block, preferably as shown, in direct metallic contact with the cylinder block through a metallic base 12 secured thereupon, said thermostatic element carrying a movable contact 13 normally separated from an insulated contact 1 to which the shunt circuit wire 9 is connected. Upon a predetermined excessive rise of the temperature of the cylinder block, as for example, when the cooling water or oil supply becomes depleted, the thermostatic element 11 which is in the form of a coil unrolls, bringing the contacts 13 and 14 together thus closing the shunt circuit and diverting the primary current from the coil 4: thus inhibiting the interrupting, functioning of the ignition circuit.

The fixed contact 14 is adjustable so that the gap between the contacts may be varied in-accordance with the degree of heat of the cylinder block at which it is desired to have the shunt circuit activated. 7

The other or alternative interrupting device, as shown, is pressure actuated, and communicates with the oil circulation system. This device may consist of a Bourdon tube 15 of electrically conductive substance arranged in spaced proximity to-the insulated adjustable fixed contact '16. The Bourdon tube being in metallic continuity with a conduit 20 of the lubrication system is thereby necessarily grounded. The fixed contact is connected by a branch wire 17 to the main shunt circuit wire 9.

When the pressure in the lubrication system diminishes through lack of suflicient oil the Bourdon tube begins to reduce its degree of curvature, and finally, at a predetermined low pressure value, it makes engagement with the fixed contact 16 thereby closing the shunt circuit.

It is obvious that either of these interrupting devices is capable alone of closing the shunt c1rcu1t and thus interruptlng the, ign1- tion system of this engine respectively in response to overheating of the engine or subpressure in the lubrication system. However, there isa peculiar advantage in the combined use of both these dev1ces,1n response to V lubrication conditions in the englne.

If the lubricant becomes fouled by sediment or diluted with gasoline, in either case impairing its viscosity and increasing its friction between the lubricated parts, the temperature of the water will rise operating the thermostatic interrupter, although the pressure responsive interrupter will. not be actuated same the pressure in the lubricatingwsystem remainsnormal. Q On the other hand, should the oil supply become depleted while the engine is standing still, as through leakage, incalculable damage might be done before the temperature of the cooling water had raised to the point at which to operate the thermostatic interrupter.

In this event, however, the pressure actuated interrupter would at once respond to the dearth of oil, closing the shunt circuit and stopping the engine.

It is of course realized that there is no pressure in the oil system until the engine has been started and that the use of a pressure responsive.interrupter in the shunt circuit would by itself preclude the possibility of starting the engine, and that therefore some means for temporarily breaking the shunt circuit must be provided at the time of starting so as to render the ignition system active. For this purpose, the invention makes provision for a manually operable release switch 18, in the shunt circuit and preferably located on the instrument board 9. This switch when opened renders the shunt circuit inactive so that the ignition circuit can function in its normal manner.

One of the advantages of the invention flows from the fact that the shunt circuit is tapped from the primary ignition circuit instead of the secondary ignition circuit, as is usual in electrical safety systems as hitherto devised. By tapping the low tension circuit, arcing between the contacts of the interrupting devices is prevented, and the reliability in the operation of the interrupting devices, is thus assured. Otherwise, the high tension current would tend to jump the gaps between the interrupter contacts interfering with the regularity of the ignition during the normal running of the engine.

Furthermore, the shunt circuit is connected into the primary circuit at a point between the transformer coil and ground, this being a part of the primary circuit where the amperage is low, thereby assuring against arcing at, the contacts of the several switches.

In those types of internal combustion engines in which it is customary to manipulate a choke rod when starting, it is convenient to combine the two operations of pulling the choke rod and operating the safety switch This may be accomplished by such a construction as is shown in Figure 2, in which the movable element 19 of the safety switch is connectedto the choke rod 21, so as to be movable therewith. An elastic or lost motion connection 22 is preferably provided between the choke rod and the'movable switch element so as to provide a greater range of movement for operating the choke rod than is necessary in operatingv the switch.

While I have in the above description endeavored to disclose a preferred and practical form of my invention it is to be understood that the principle of the invention may be exemplified in other 'iorms andarrangements of parts, Without departing fromthe spirit and scope of the appended claim.

Having thus described the invention, What is claimed is: Y

In combinatiomin an internal combustion engine, an ignition system comprising primary and secondary circuits, a normally open circuit in shunt with the primary circuit of said ignition system, and normally open circuit closing means in said shunt circuit re- HARVEY HUBER ESLINGER. 

